Technical Field
The present disclosure is related to a scheme for scheduling a carrier aggregation (CA), and more particular to a scheme for scheduling the CA based on Long Term Evolution (LTE) system.
Related Art
In the traditional LTE system R (release) 10 developed by 3GPP (3rd Generation Partner Project), the CA is introduced as one of the key techniques, a main idea is that user equipment (UE) may work on a plurality of carriers at the same time, and the CA may improve peak value rate of a single UE. In LTE CA, the UE is configured with one Pcell (primary cell) and one or more Scells (secondary cell). For FDD (frequency duplex division) LTE, one serving cell includes at least one downlink carrier of lone downlink carrier, one uplink carrier). For TDD (time duplex division) LTE, one serving cell includes one carrier. In LTE RIO, the UE supporting the CA may maximally be configured with five serving cells, and the UE may only transmit the PUCCH information on the Pcell.
In the existing LTE system, the CA supports a cross carrier scheduling, i.e. the base station transmits a downlink signaling on a first carrier to schedule a wireless signal transmission on the second carrier. The base station uses a CIF (carrier indicator field) in the DCI (downlink control information) to indicate a target carrier to be scheduled. The CIF is indicated by three bits located on the header of the DCI.
A new research topic (RP-132085) is adopted in the 66th plenary of 3GPP RAN (radio access network), i.e. enhanced CA. In enhanced CA topic, a maximum number of the supported serving cells is raised to 32.
For enhanced CA, an intuitive method is to increase a number of bits of the CIF (for example, the number of bits is increased to 5 bits) to ensure that the base station may schedule any target carrier. However, the above intuitive method causes an increase of total number of bits of DCI, thereby occupying more air interface resources by the DCI or reducing the receiving performance of the DCI. For the problem, the present disclosure discloses an enhanced carrier aggregation scheduling method and device.